Most challenging robotic mission ever attempted is a success so far.

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Mars Science Laboratory arrived at its destination Sunday night at 10:31pm Pacific Time. The MSL team at NASA's Jet Propulsion Laboratory's control center in Pasadena was ecstatic; the mission control room was flooded with jubilant pandemonium. According to NASA Administrator Charlie Bolden, who was there along with Deputy Administrator Lori Garver and Presidential Science Advisor John Holdren, "Everybody in the morning should be sticking their chests out saying, 'That's MY Curiosity rover on Mars!'" The rover is checking out in perfect shape so far, and soon the science will begin.

Progress reports rolled in last night at a rate of about one per minute. Each time a milestone in the intricate system was transmitted home, the team clapped and broke out in spontaneous laughter.

The first two pictures from Curiosity as they were displayed for JPL mission control

Photo credit: NASA JPL video screen capture

Ecstasy breaks out in the JPL Mission Control Room.

Photo credit: NASA JPL video screen capture

Some events in the control room timeline as they arrived (14 minutes after they actually took place on Mars):

Touchdown time was 10:14:39pm Pacific Time, with 140.46kg of fuel remaining (out of 400kg to start) in the descent stage as it flew away. There's no doubt we'll visit that descent stage again some day.

Scientists and engineers at JPL will spend the next several hours sorting through data relayed from two other spacecraft in orbit around Mars. Mars Odyssey and Mars Reconnaissance Orbiter were catching the telemetry from Curiosity and sending it home to Earth.

At the press conference this morning, John Holdren said Curiosity is "the most challenging mission ever attempted in the history of robotic exploration." Anyone who has watched the NASA JPL video Seven Minutes of Terror (the website has been knocked offline due to large amounts of traffic) knows why. The Mars Science Laboratory spacecraft weighed almost four metric tons at launch. Even after using much of its fuel, it was far too large to land using anything NASA has ever tried before.

There are basically three ways to land a spacecraft on Mars, which has an atmosphere one percent of the density of Earth's. Reentry shields and parachutes work to slow down the spacecraft, but not nearly as well as they do on Earth.

The Viking probes used rockets to slow the spacecraft in the air and lower them gently to the Martian surface. The Mars Exploration Rovers, Spirit and Opportunity, used a similar system to suspend them 10 to 15 meters above the surface. They then popped giant airbags and fell the rest of the way.

Curiosity's landing system worked much the same way as its predecessors' down to a few tens of meters above the surface. To begin, a giant 4.5m aerodynamic heat shield, the largest ever flown in space, slowed the spacecraft down to about 470 meters per second. That was slow enough for Curiosity's 16m incredibly strong, supersonic parachute to pop out and slow Curiosity down further to about 100 meters per second—better, but still pretty fast.

At that point, about 1.8 kilometers above the ground, the parachute was cut loose, and the descent stage's rockets began firing. During this time, Curiosity began to unfold. The rockets lowered the craft down to only 7.6 meters above the surface, just a few stories. So far, very similar to previous probes, except much larger.

But at 900kg, Curiosity was much too large to drop to the surface using giant airbags. Instead, it was lowered to the surface using cables from the descent stage. Once landed, explosive bolts detached the cables and the "skycrane" sped away to land well out of the way.

The landing site itself is in Gale Crater, named for Walter Frederick Gale, the amateur Australian astronomer who spotted what he thought were canals on the Martian surface. Gale Crater contains a mountain of layered rocks that looks like a great geological target, a smooth region of material washed down from the sides that makes another good target and a place to land without boulders, and some very brightly colored, very dense rocks that may have once formed a dry lakebed. These rocks are a good place to check for organic molecules and evidence of life on Mars.

Curiosity is a mobile laboratory of unprecedented scale. It has seventeen cameras and several remote sensing instruments, including a laser-driven breakdown spectrometer, an X-ray spectrometer, an X-Ray diffraction instrument, a radiation assessment detector, a pulsed neutron source and detector, and a meteorological package. It also houses the entry descent and landing instrumentation, plus hazard avoidance and navigation cameras. To land all of this instrumentation intact is an amazing victory for the seven countries that participated in the spacecraft: Finland, Spain, Canada, Russia, France, Germany, and the United States. It's especially amazing that we're back up to two operating rovers on Mars again, counting Opportunity.

Right now, Curiosity is being checked out on the surface, but it's transmitting video, and all is very, very well in Pasadena. It's doubtful that the Curiosity team (or Curiosity's many fans and followers) will sleep for the next day or two.

Promoted Comments

When I first saw the sheer complexity of this Mars landing, I thought this was so complex that it was bound to fail somehow. I'm glad to see I was wrong. That's an heck of an achievement that the NASA pulled off.